.TH iscntrl 3 "" "" ""
.SH SYNOPSIS
iscntrl \- control character predicate
.SH ANSI_SYNOPSIS
#include <ctype.h>
.br
int iscntrl(int 
.IR c );
.br
.SH TRAD_SYNOPSIS
#include <ctype.h>
.br
int iscntrl(
.IR c );
.br
.SH DESCRIPTION
.BR iscntrl 
is a macro which classifies ASCII integer values by table
lookup. It is a predicate returning non-zero for control characters, and 0 
for other characters. It is defined only when 
.BR isascii (<[c]>)
is
true or 
.IR c 
is EOF. 

You can use a compiled subroutine instead of the macro definition by
undefining the macro using `
.BR #undef iscntrl '.
.SH RETURNS
.BR iscntrl 
returns non-zero if 
.IR c 
is a delete character or ordinary
control character (
.BR 0x7F 
or 
.BR 0x00 --<<0x1F>>).
.SH PORTABILITY
.BR iscntrl 
is ANSI C.

No supporting OS subroutines are required.
.SH SOURCE
src/newlib/libc/ctype/iscntrl.c
